1)n. a big, dumb, rather oafish man
2)n. description that combines the worst aspects of being lazy and fat
3)n. a combination of 1) and 2)

The word galoot is rarely used completely seriously. Instead, it is usually used as playful exaggeration or in self-deprecation. On those rare occasions when it is more directly applied (to others) its light nature gives it the form of mild reproach.

1) You're just a dumb galoot, but I love you anyway.
2) I haven't gotten off my ass all day! I'm such a galoot!
3) You'd have a hard time finding a job, even if you weren't having such a hard time getting out of bed, you big galoot! Don't you know potato chips cost money?